THURSDAY, Dec. 7, 2017 (HealthDay News) -- As the baby boomer population ages, the number of Americans with Alzheimer's disease will double by 2060, researchers report.

The study findings, which show cases of Alzheimer's and mild cognitive impairment going from 6 million this year to 15 million in four decades, highlight the need to better identify people with a brain-related disease, and to slow its progression.

"There are about 47 million people in the U.S. today who have some evidence of preclinical Alzheimer's," said study author Ron Brookmeyer. He is a professor of biostatistics at the Fielding School of Public Health at University of California, Los Angeles.

"Many of them will not progress to Alzheimer's dementia in their lifetimes. We need to have improved methods to identify which persons will progress to clinical symptoms, and develop interventions for them that could slow the progression of the disease, if not stop it altogether," Brookmeyer said in a UCLA news release.

The researchers used information from large Alzheimer's studies to create a computer model to estimate the number of future Alzheimer's cases.

The investigators determined that by 2060, about 5.7 million Americans will have mild cognitive impairment and another 9.3 million will have full-blown Alzheimer's. Of those with Alzheimer's, about 4 million will require intensive care, such as that provided in nursing homes.

"Estimates by disease state and severity are important because the resources needed to care for patients vary so much over the course of the illness," Brookmeyer said.

People with mild cognitive impairment (MCI) have significant short-term memory loss but do not necessarily have problems with daily functioning. While those with MCI are more likely to go on to develop Alzheimer's disease, MCI does not always lead to dementia. In full-blown Alzheimer's, the symptoms are more severe, and include memory loss as well as impaired judgment and thinking, problems with performing normal daily activities and, sometimes, personality changes.

The study was published Dec. 7 in Alzheimer's and Dementia: The Journal of the Alzheimer's Association.